CNBC’s Ron Insana warns there are a variety of risks to this aging bull market, "from economic to political to geo-political issues that could suddenly appear on the horizon."

But the risk he is most concerned about going into 2017 is “if the economy accelerates and inflation moves above the Fed's 2 percent target, the central bank could move rates up farther and faster than currently anticipated by the stock market,” he wrote for CNBC.com.

“Other developments that could most likely undo the market's recent gains include a trade war with either Mexico or China, or both at the same time,” he said.

A two-front trade war "would most certainly lead to a major disruption of global economic activity, a devastating hit to corporate bottom lines and, as we have seen in the past, a potentially devastating recession," he explained.

“Trump reportedly recently met with Mexico's richest man, Carlos Slim, which some said was an effort to calm the nerves of businessmen and politicians south of our border. The tensions with China are rising much more quickly and could be the real threat to future global growth,” he said.

“Add to the trade tensions, the attempts by China to exert military power through much of Asia, and international waters in the South China Sea Asia and an accidental shooting match, thought not an all-out war, have to be considered as an event with a greater than zero probability, or risk," Insana said.

Insana admits it is hard to make a macro call that suggests the world is on the precipice of such a tumultuous period. "But we must remain alert that the current "era of good feeling" I wrote about last week can change quickly," he wrote.

"For now, the markets are forecasting a financial utopia. They deserve the benefit of the doubt for the foreseeable future, unless, and until, the specter of a more dystopian environment is reflected in the prices of stocks, bond and commodities. In this brave new world, that is simply not the case right now."

Insana isn't the only financial guru to warn that the market's Trump honeymoon may soon end.

Nobel laureate economist Robert Shiller warned that investors shouldn't get too comfortable, as the Trump rally could end up like Calvin Coolidge's run nearly a century ago. Coolidge was president during the Roaring '20s, before the decade-long Great Depression started in 1929, CNBC.com explained.

"It could be like ... Coolidge prosperity. It went for a while and it ended badly," he said.

To be sure, for the year:

The Dow is up 2,508.78 points, or 14.4 percent.

The S&P 500 is up 219.85 points, or 10.8 percent.

The Nasdaq is up 455.28 points, or 9.1 percent.

The rally after Trump's victory was built on expectations of reduced regulations, big tax cuts and a large fiscal stimulus. Now signs are emerging from the Trump camp that harsher trade policies that could jeopardize the honeymoon are likely in the offing, and investors would be well advised to give those prospects more weight when gauging how much further an already pricey market has to run, Reuters reported.